BEES, WASPS, ANTS, ETC. 



527 



The PoiXPiLiD^ is a larger and more important family than either of the two pre- 

 ceding. Its representatives are well known and feared, on account of their formi- 

 dable sting. They are slender in form, usually black in color, occasionally variegated 

 with red or orange, and with dusky, reddish, or black wings. The tropical species are 

 often very large, and, in fact, among the species of the genus Pepsis are to be found 

 the largest of known Hymenoptera. Pepsis heros of Cuba is over two inches long. 



Fig. 652. — Wasps, a, Pompilius nataietisiSf stinging a spider; 6, A^enia 2m7ictum and its cellj c, J'ompUius 

 trivialis ; d, its larva feeding on a spider; e, Prwcnemis variegaius. 



The insects of this family have verj' long, slender legs. The abdomen is oval and 

 attached to the thorax by a very short peduncle ; the jsronotum is quadrate, and tlic 

 wings have two or three perfect submarginal cells. 



Tiie name " sand-wasps," which has been applied to these insects, is derived from 

 their almost universal habit of digging burrows in sandy places, and pi-ovisioning them 

 with stung insects. There are, however, exce])tions to this rule. Pompilius petialvu- 

 tus has been observed forming a nest of clay in the chinks of a waXl, and the entire 

 genus Ceropales seems to be parasitic or in- 

 quilinous, laying its eggs in the nests of fos- 

 sorial. species. Ceropales rujicollis has been 

 bred from the mud-nest of Agenia, a member 

 of the same family, and the American C. 

 nofiventris has been similarly bred from the 

 cells of Agenia. bombycina. 



The typical genus Pompilius is one of 

 large extent, and over five hundred species 

 are known. The so-called "tarantula-killer" 

 of Texas (^Pompilius formostts) stores its 

 burrow with the great southwestern spidei-, 

 Mygale hentzii, erroneously known as a taran- 

 tula. Its burrow is five inches deep, and 

 but one Mygale and one egg are deposited in each. Occasionally the spider succeeds 

 in capturing the wasp, but this does not often happen. The wonderful effect of the 

 stino- is well shown by Dr. Lincecum, who states that he has found spiders stored 

 away, on which the egg of the Pompilius had failed to hatch, and that, after an evident 



Pig. ^53.— CeropaU 



